Hobbing machine



Sept. 9 1924. Re. 15,912

K. L. HERRMANN noamns ncnmz I mail-Shoot 1 Original Filed Aux-11 17, 1922 ATTORNEY Reisaued Sept. 9, 1924.

UNITED-STATES PATENT OFFICE.

kAaL L. rin'nnunivlv,

or nn'rnorr, mrcmean, lASSIGNOR TO s'ron'nsms' cosrona- Tron, A conrona'rrorr or NEW Inseam, V 1

Honsme Y original No. 1,444,247, dated February 6, 1923, Serial No. 554,060, flled A prll. 17', 1922. Application for reissue filed January 9, 1924. Serial No. 685,281.

To all whom it may Be it known that I, KARL L. HERRMANN,

a citizen of the United States of America, residing at- Detroit, in the county of Wayne 6 and State of Michigan, have invented certain new and useful Improvements in Hobbing Machines, of which the following is 'a specification, reference being had therein to the accompanying drawings. This invention relates to gear cutting machines and more particularly to that class of such machines known as hobbing machines.

An object of the invention is to simplify the construction whereby a minimum number of gears is employed to secure the proper relative movement between the hob rangement and combinationof parts.

With th above and other ends in view the invention consists in the matters herein-' after set forth and more particularly pointed out in the appended claims, references being had to the accompanying drawin in which igure 1 is a plan viewof the machine illustrative of an embodiment of the invention and with portions broken away and in section to more clearly show the construction.

Figure 2 is a side elevation of the same with: portions broken away and in section. Figure 3 is a artial end elevation of one 85 end of themac inc.

Figure 4 is an elevation end. I

In the cutting of gears or worm wheels of the opposite by means of a cutter known as a hob, it is.

necessary 'to rotate the work or blank in timed relation to the rotation of the hob and to move the blank and hob relatively and in-timed relation to the other movenients. -These relative timed movementshave been secured through the employment of a complicated gearing for transmitting the proper motion but because of such comthus simplifying the construction and eliminating many of the difliculties and disadvantages of the more involved constructiom As illustrative of an embodiment of the invention a. machine is shown in the accomlike beveled gear 6 secured upon a, shaft 7 mounted in a bearing 8. formed integral with a gear casing 9 whichgear casing is provided with a bearing 10 to receive the shaft 3 and'swing about the axis of said shaft. The shaft 7 forms the spindle upon which the rotary tool or hob 11 is secured and to hold the casing 9 carrying said spindle, in proper adjusted position relative to a work spindle 12, and also to form a pan or receptacle beneath the hob or cutter, a. pan 13 is secured integral with the bearing portion 8 of the casing 9 and this pan has ears 14 thereon provided with slots 15 to receive bolts 16 engaging screwthreaded openings in the frame 1 for adjustably holding the casing 9 of which the pan 13 forms a part, the side of said pan being securely held against the side of the frame by means of said bolts. By loosening these bolts and swinging the casing together with the spindle 7 carried thereby about the axis of the main driving shaft 3, the hob or cutter 11 may be adjusted toward or from the work. I

A long bearing 17 is provided on the frame 1 for the enlar d portion 18 of the work carrying spindle 12, the work consisting of a series of blanks 19 being secured upon the reduced end portion of this spindle in any suitable manner as by a nut 20.

Mounted upon the opposite end of the spindle 18 is a let e spur gear 21 by means of which the wor spindle is rotated at a very low speed, motion being transferred from the main drive shaft 3 through a small inion 22 on the end of the drive shaft w ich pinion is adaptedto mesh with a spur gear 23 which is secured to or formed integral with an elongated gear or pinion 24' in mesh with the large pinion 21. The s of rotation of the main drive shaft is fore panying drawings com rising a suitable through the several gears greatly reduced to the hob, the horizontal plane of the work s indle being above the plane of the axis of t e hob so that upon longitudinal movement of the work spindle the work will be moved across the hob, the hob being held in the position to which it is adjusted relative to the work spindle, by adjusting the casing 9 rotativelv about the axis of the driving shaft 3. The feeding of the work to the hob is accomplished by providing a screw shaft 24 which shaft is mounted in a suitable bearing 25 on the frame and held by said heating against longitudinal movement but free to turn therein, said screw shaft extending into a bore in the end of the spindle 18. Within the bore of the spindle is secured in any suitable manner as by a pin 26,.a nut 27 having an internal screw thread to receive the screwthreaded shaft 24. Upon the transmission of motion to the large gear 21, the work spindle-will be slowly rotated and as the screw shaft 24 is held against rotation by means of a hand wheel 28 on its outer end. having a lock bolt 29 for locking the wheel against turning, the turning of the spindle which carries the nut 27 will feed the spindle forwardly and bring the work carried by its opposite end into engagement with the hob. This feeding movement of the work spindle is therefore in timed relation to the rotation of the spindle and the rotation of the hob and by properly proportio'ning the diffe znt speeds of rotation and the pitch of the screw 24, the desired form of teeth will he cut by the hob in the peripheries ofthe blanks as these blanks are fed horizontally 'and with a simultaneous movement across the hob. When the spindle has reached the end of its longitudinal movement and the blanks have been carried across-the hob and the cutting operation completed, the spindle may be quickly returned to the position shown in the drawings, by releasing the latch bolt 29 and rotating the screw shaft 24 by means of a hand wheel 28. The finished work is then removed from the spindie and other blanks-secured in place thereon and the operation repeated.

As the work s indle is moved longitudinally, it carries t e large gear wheel 21 with it, said gear wheel'sliding in mesh-with the long gear 24 during the reciprocation of the spindle. The gears 23 and 24 are idler ion 22 to the large gear 21 and these gears 23 and 24 are carried by a suitable bracket 30 which is adjustably secured to the frame I 'l by means of'a locking bolt 31 passing througha slot 32 in the bracket. The meshing engagement of these idlers with their gears may therefore be adjusted or may be removed and others substitutedhaving a different number of teeth for the purpose of changing the work spindle and the hob or spindle. The depth of tooth to be formed on the blanks may be varied by adjusting the hob toward or from the blanks, said adjustment being accomplished by swinging the casing 9 which carries the hob spindle, about the axis of the driving shaft 3 as previously described, and to assistin this adjustment which must of necessity be very minute and. accurate, a; pedestal 33 is provided beneath the pan 13 and in the upper end of this pedestal is mounted a screw shaft 34 carrying an index wheel 35 upon its upper end with a pointer 36 secured to the pedestal and extendin across the face of the wheel,

the ratio of rotation between the upper ent of the shaft abutting against a lug 37 on the lower side of the pan so that by turning the screw shaft by means of the index wheel, the casing of frame of which the pan forms a part and which carries the hob spindle, may be accuratel raised or lowered and such adjustment wi l be indicated by the wheel. After the proper adjustment of the hob relative to the work is thus secured, it is held in adjusted position by tightening the bolts 16. By mounting the hob spindle for rotation in fixed relation to the work, and arranging the work carrying spindle for movement across the hob, the necessary relative and timed rota-tive and feeding movements may besecured through the employment of aminimum number of gears and a very simple and efficient construction.

Obviously any desired relative speeds of work spindle and hobmay be secured to suit the particular work in hand and it is also obvious that other changes may be made within the scope of the appended claims, in the articular combination and arrangement 0 longitudinally movable angularly across the axis of'the other, a stationary support in which saidwork carrying spindle is journalled, means for driving said spindles simultaneously in timed relation to each other, and means including a non-rotatable memparts, without departing from the spirit of the invention and I do.

i the axis of the. other,

her and a member r' 'd withsaid lo 'tudinallf movable spin e for moving t e latter ongitudinally.

2. In a machine of'the class described, the combination of a generating-tool spindle and a work carrying spindle one of which is longitudinally mova means for driving said spindles simultaneously in timed relation to each other, means including a nonrotatable member and a member rigid with said lon itudinally movable spindle for movin t e latter longitudinally, and indepen ent means for operating the nor: mally non-rotatable member to cause the longitudinally movable spindle to move to its initial position.

3. In a machine of the class described, the

of a main drive shaft and a hob spindle in radial relation thereto, means for holding said spindle in a fixed sition, a work carrying spindle longitu mally movable angular y across the axis of the hob spindle, and means for imparting a rotary motion to said spindles in timed relation to each, other and a longitudinal movement to the work spindle in timed relation to the relative movements of said spindles. i

5. In a bobbing machine, the combination of a hob spindle, means for holding said spindle ina fixed position, a'work .carrying1 spindle longitudinally movable an lar y across the axis of the hob spindles, means for imparting a rotary motion to said spindles, and means comprising a lurality of elements for moving said spin e longitudinally only one of said elements bein movable and solely-by the rotation of sai work spindle.

6. In a bobbing machine, the combination of a hob spindle, spindle-in a fixed position, a work carrying splndle longitudinally movable angularly across the axisof the hob spindle, means for imparting rotary motion to said spindles simultaneously in timed relation to each other, and means including a normally nonrotatablemember and a member carried by the work spindle tation thereof for gitudinally.

7. In a hobbing machine, thecombination moving said spindle lonle angularly across sha means fOr holding saidand operative by the roof a hob spindle, means for spindle in a fixed position, a work carrying spindle longitudinally movable angularly acrossthe axis of the hob spindle, a main driving shaft, means for transmitting inotion from said shaftrto said spindles to rotate the same in timed relation to each holding other, and means including a screw andnut oneof which is normally non-rotatable and the other rotated by said work spindle for moving said spindle longitudinally.

8. In ahobbing machine, the combination of a hob spindle,a rotating shaft, a member extending radially from and supported to swing about theaxis of said shaft and forming an adjustable support for said hob spindle, means for holding said member in t e fposition to which it is swung about said dle arrange at an angle to the axis of the hob spindle to project the work carried thereby across a hob carriedby the hob spindle, gearing between the'shaft and the hob spindle, and-means operated solely by the rotation of the work spindle for movin said work spindle longitudinally in time relation to the rotative movements of said spindles.

9. In a hobbing machine the combination of a work spindle, a main drive spindle par allel thereto and a pivotally supported hob spindle whose pivotal line crosses its axis, and having a hob receiving portion adjustable toward said work spindle, means for producing timed rotation and cross move ment between, and for adjustingand holding the relative positions of, dle and said hob spindle.

10; In a hobbing machine, a work spindle and a hob spindle having a hob receiving portion, a hob mounted thereon, means for simultaneously rotating said spindles 'in timed relation, said hob spindle pivoted about a linecrossing its axis, and means for varying the distance between said work spindle and said hob receiving portion along an arcuate path through the axis of said work spindle and said hob receiving portion.

11. In a gear cutting machine. the coming the relative position of, saidelements." 1

12. In a bobbing machine, a hob spindle pivoted about a line crossing its'axis, a hob mounted on said spindle, and a work spin-' dle, means for simultaneously rotating said spindles in timed relation the distance .be-

tweenthe work spindle and hob spindle bemg adjustable along an arcuate path and a Ion 'tudinally movable work spinsaid work spin-- 'bination of a work spindle, and a cutter the distance between said'line and the axis of the work spindlebeing invariable.

13. Ina hobbing machine, a non-swinging longitudinally movable work spindle, and

a swl gmg non-longitudinally movable hob spindle having a hob receiving portion theredistance between work spindle dle one of which is longitudinall angularly across theaxis-of the ot er, means I mentioned one of which is stationa being on, a hob mounted on said spindle, and the and said hob receiving portion being variable in an arcuate path t rough the axis of the work spindle and about a center line which crosses the axis of the hob spindle.

14. In a hobbing machine, the combination of a hob spindle, means for holding said spindle in a fixed relation, a work-carrlying spindle longitudinall movable angu arly across the axis of the ob spindle, means for imparting a rotary motion to said hob spindle, a driving device mounted on and --movable with said work-spindle,means for driving said device, and means operated by rotation of said work-spindle for moving said work-spindle longitudinally.

15. In a hobbingmachine, the combination of a hob spindle and a work-carrying spindle one of which is longitudinally movableangularly across the axis of the other, means for implarting a rotary motion to said longitudina y movable spindle including a gear mounted on said longitudinally movable spindleand movable therewith and a gear constantly in mesh'with said first-mentioned gear, and means includinga nut and a screw one of which is stationar and the other secured to said longitudinally movable spindle for movin the same lon itudinally.

16. In a hob ing machine, t e combination of a hob spindle and a work-carrying spinmovable for im arting a rotar motion to said longitudina l movable s mdle including a gear mounte on said ongitudinally movable spindle and movable therewith and a fixed long ar constantly in mesh with said firstgear. and in sliding relation thereincluding a 'nut and a' screw and the other secured to said longitudina ly movable spindle for moving the latter longitudinally.

to, and means 1 j 17. In a bobbing machine, the combination of a hob spindle, a work-carrying spindle, zone of which is longitudinally movable angularly 'acrossthe axis of the other, means for imparting rotary motion to'said spindles in time relation, and means comprising a riut and a screw one of which is stationary and the other secured to said longitudinallymovable spindle for moving the latter longitudinally, the normally stationary member operable to return the longitudinally movable spindle-to its initial position.

18. In a bobbing machine, the combination of a'hob's indle, a work-carrying spindle, one of wliiich' is longitudinally movable v v a ary and the other secured to, and mounted.

within, said longitudinally movable spindle for movingjthe latter longitudinally, and a. hand-wheel on the normally stationary memher for rotating the latter to return the longitudinally movable spindle to its initial position.

, 19. In a hobbing machine comprisinga work spindle, a rotary shaft, a hob spin 1e, and means for driving said spindles and shaft in timed relation, said shaft and said work spindle bein parallel and the axis of the hob spindlefiiemg across the axes of said first-mentioned spindle and shaft and in substantially the same plane as the axis of said shaft.

20; In a hobbing machine comprising a work spindle, a rotary shaft, a hob spin 1e, gearing between said rotary shaft and said spindles 'for driving said spindles and shaft in timed relation, said shaft and said work spindle being parallel and the axis of the hob spindle crossing the axes of said firsts mentioned spindle and shaft and in substantially the same planeas the axis of said shaft, and means for moving one of said spindles longitudinally angularly across the axis of the other.

21. In a hobbing machine compris ng a work spindle a rotary shaft, a hob spm le, means including ars between said hob spindle and shaft and also sliding intermeshing gears between said work spindle and shaft for driving said spindles and shaft in timed relation, said shaft and said work spindle being paralleland the axis of the hob spindle crossing and the same plane as means, comprising a nut and a screw one of which is stationary and the other secured longitudinally.

in substantially the axis of said shaft, and" ,22. In a bobbing machine comprisin a work spindle, a rotary shaft, a hob s m e, means for driving sai spindles an shaft in timed relation, said shaft and said work spindle being parallel and the 'axis of the hob spindle being across the axes ofsaid firstmentioned spindle and shaft and in substantially the same plane as the axis ofsaid shaft, a casing supporting said hob spindle and pivotally su ermit angular a I ustment lle with respect to the work sp means for securing the casing in adjusted position.

, 23(In a work spindle, a rotary shaft, a hob spindle means includin gears for driving said spindles and s aft in timed relation, a carrying said hob sp ndle and ofthe hob spinindle, and

ported on said shaft to pivoted on said shaft to permit angular adjustment of the hob spindle with respect to the work spindle, said casin also form ing ahousin for the gearing etwee'n said shaft and ho spindle, and means for adjustin said casing.

24. in a hobbing machine, a work spindle and a hob spindle having a hob receiving portion thereon, bne of said spindles being pivoted about a line crossing the axis of one of said spindles, a hob on said receiving portion, means for varying the distance between said work spindle and said hob along an are through the axis of the work spindle and said hob, and means for rotatin said spindles simultaneously in timed relation.

25. A hobbing machine comprising a hob supporting spindle having a hob mounted thereon and a work supporting spindle, a prime mover, an intermediate shaft operatively connected intermediate its ends directly to said prime mover, a bevel-gear mounted at oneend of said intermediate shaft, and a spur-gear mounted at its other end, a bevel-gear on said hob su porting spindle meshing directly with st-mentioned bevel-gear for driving the hobsupporting spindle, means spur-gear directly meshing with including a said abovementioned spuran for drivin the worksupporting spin 1e, and means or effecting a progressive relative translation between said spindles in a. direction parallel with the work-supporting spindle.

26. A hobbing mac ine comprising a hob supporting spindle having a hob mounted thereon and a work supporting spindle, a power driven shaft, a prime mover operatively connected directly to said shaft, :1 bevel-bear secured directly to one end of said shaft and a spur-gear secured directly to its other end, a bevel-gear meshi directly with said first-mentioned bev f gear and mounted directly on one of said spindles, means consisting of spur gears, one of which meshes directly with said first-mentioned spur-gear for propelling the other spindle, and means for efl'ecting a pro ressive relative translation between said spindles in a directionparallel with the work-supporting spindle.

Signed by me at Detroit, Michigan, .U. S. A., this 7 day of Jan., 1924.

KARL L. HERRMANN. Witnesses: 1

Honosox S. Pmnon, DONAL B. Warm. 

